• Journal of Ecology and Environment
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• v.42 no.4
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• pp.155-162
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• 2018

Background: In ecosystem carbon cycle studies, distinguishing between $CO_2$ emitted by roots and by microbes remains very difficult because it is mixed before being released into the atmosphere. Currently, no method for quantifying root and microbial respiration is effective. Therefore, this study investigated the relationship between soil respiration and underground root biomass at varying distances from the tree and tested possibilities for measuring root and microbial respiration. Methods: Soil respiration was measured by the closed chamber method, in which acrylic collars were placed at regular intervals from the tree base. Measurements were made irregularly during one season, including high temperatures in summer and low temperatures in autumn; the soil's temperature and moisture content were also collected. After measurements, roots of each plot were collected, and their dry matter biomass measured to analyze relationships between root biomass and soil respiration. Results: Apart from root biomass, which affects soil's temperature and moisture, no other factors affecting soil respiration showed significant differences between measuring points. At each point, soil respiration showed clear seasonal variations and high exponential correlation with increasing soil temperatures. The root biomass decreased exponentially with increasing distance from the tree. The rate of soil respiration was also highly correlated exponentially with root biomass. Based on these results, the average rate of root respiration in the soil was estimated to be 34.4% (26.6~43.1%). Conclusions: In this study, attempts were made to differentiate the root respiration rate by analyzing the distribution of root biomass and resulting changes in soil respiration. As distance from the tree increased, root biomass and soil respiration values were shown to strongly decrease exponentially. Root biomass increased logarithmically with increases in soil respiration. In addition, soil respiration and underground root biomass were logarithmically related; the calculated root-breathing rate was around 44%. This study method is applicable for determining root and microbial respiration in forest ecosystem carbon cycle research. However, more data should be collected on the distribution of root biomass and the correlated soil respiration.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.1
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• pp.56-64
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• 2017

Soil quality has been regarded as an important factor for maintaining sustainability of ecosystem. Main purpose of this research was i) to select minimum factor for predicting biomass, and ii) to calculate soil quality index for biomass according to soil chemical properties. Result showed that soil pH, electrical conductivity (EC), soil organic matter (SOM), cation exchange capacity (CEC), and available phosphorus are minimum data set for calculating biomass production in soil. Selected representative soil chemical properties were evaluated for soil quality index and rated from 1 to 5 (1 is the best for biomass production). Percentage of each grade in terms of biomass production in national wide was 14.52, 35.23, 33.03, 6.47, 10.75% respectively. Although, only soil chemical properties were evaluated for calculating optimum soil quality, result of this research can be useful to understand basic protocol of soil quality assessment in national wide.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.2
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• pp.109-115
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• 2004

To elucidate the effects of composted pig manure on soil biochemical properties, composted pig manure was amended in a sandy loam soil and Chinese cabbage was grown. Composted pig manure treatments included 8, 29 and $57Mg\;ha^{-1}$ for CM-08, CM-29, and CM-57 plots, respectively. Biomass contents and enzymes activities in the non-rhizophere soil were measured. Activities of protease, phosphomonoesterase and dehydrogenase in the plot CM-57 increased to 2.3, 1.6, and 2.4 fold as compared with those of the control plot. Soil microbial biomass contents increased in proportion to the application rates of compost and biomass C, N, and P in the plot CM-59 were 4.3, 3.4, 2.8-fold higher than those of control p1ot(no fertilizer), respectively. During cultivation of Chinese cabbage, biomass C and N were higher in the middle growth stage, although biomass P was the highest in the early growth stage. The average ratio of biomass C:N:P was 11:2:1, and proportion of biomass C and N in the soil organic C and N was 1.1 and 3.6%, respectively. Activities of protease and dehydrogenase had significant correlations with biomass C and P.

• Journal of Forest and Environmental Science
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• v.34 no.1
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• pp.12-23
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• 2018

Quantitative information on biomass and available nutrients are essential for developing sustainable forest management strategies to regulate atmospheric carbon. An attempt was made at Chilapatta Reserve Forest in Duars region of West Bengal to quantify its above and below ground carbon along with available "N", "P" and "K" in the soil. Stratified random nested quadrats were marked for soil, biomass and litter sampling. Indirect or non-destructive procedures were employed for biomass estimation. The amount of these available nutrients and organic carbon quantified in soil indicates that the forest soil is high in organic carbon and available "K" and medium in phosphorus and nitrogen. The biomass, soil carbon and total carbon (soil C＋C in plant biomass) in the forest was 1,995.98, 75.83 and $973.65Mg\;ha^{-1}$. More than 90% of the carbon accumulated in the forest was contributed by the trees. The annual litter production of the forest was $5.37Mg\;ha^{-1}$. Carbon accumulation is intricately linked with site quality factors. The estimated biomass of $1,995.98Mg{\cdot}ha^{-1}$ clearly indicates this. The site quality factor i.e. tropical moist deciduous with optimum availability of soil nutrients, heavy precipitation, high mean monthly relative humidity and optimum temperature range supported luxuriant growth which was realized as higher biomass accumulation and hence higher carbon accumulated.

• Korean Journal of Environmental Agriculture
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• v.19 no.5
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• pp.375-381
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• 2000

Quantifying the changes of soil microbial biomass and activity of enzymes are important to understand the dynamics of active soil C and N pools. The dynamics of soil microbial biomass C and N and the activity of enzymes over entire growth period of soybean-(Glycine max (L) Merr.)-wheat (Triticum aestivum L.) sequence on a Typic Haplustert as influenced by organic manure and inorganic fertilizer N were investigated in a field experiment. The application of farmyard manure at 4 to 16 $Mg{\cdot}ha^{-1}\;y^{-1}r^{-1}$ along with fertilizer nitrogen at 50 or 180 $kg{\cdot}ha^{-1}$ increased the mean soil microbial biomass from 1.12 to 2.05 fold over unmanured soils under soybean-wheat system. Irrespective of organic and chemical fertilizer N application, the soil microbial biomass was maximum during the first two months at active growing stage of the crops and subsequently declined with crop maturity. The mean annual microbial activity was significantly increased when manure and chemical fertilizer at 8 $Mg{\cdot}ha^{-1}$ and 50/180 N $kg{\cdot}ha^{-1}$, respectively were applied. The C turnover rate decreased by 47 to 72 % when the level of farmyard manure was increased from 4 to 8 and 16 $Mg{\cdot}ha^{-1}$. There were significant correlations between biomass C, available N, dehydrogenase, phosphatase and yield of the crops.

• The Plant Pathology Journal
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• v.18 no.1
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• pp.30-35
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• 2002

The hyphal growth and biocontrol efficacy of Trichodemo harzianum in soil may depend on its interactions with biotic components of the soil environment. The effect of soil microbial biomass on growth and biocontrol efficacy of T. hanianum isolate ThzIDl-M3 (green fluorescent protein transformant) was investigated using artificially prepared different levels of soil microbial biomass (153,328, or 517ug biomass carbon per g of dry soil; BC). The hyphal growth of T. harzanum was significantly inhibited in the soil with 328 or 517 $\mu$g BC compared with 153 ug BC. When ThzIDl-M3 was added to the soils as an alginate pellet formulation, the recoverable population of ThzIDl-M3 varied, but the highest population occurred in 517ug BC. Addition of alginate pellets of ThzIDl-M3 to the soils (10 per 50 g) resulted in increased indigenous microbial populations (total fungi, bacterial fluorescent Pseudomonas app., and actinomycetes). Furthermore, colonizing ability of ThzIDl-M3 on sclerotia of Sclerotinia sclerotiorum was significantly reduced in the soil with high revel of BC. These results suggest that increased soil microbial biomass contributes to increased interactions between introduced T. harzianum and soil microorganisms, consequently reducing the biocontrol efficacy of 1T. harzianum.

• The Korean Journal of Ecology
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• v.17 no.2
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• pp.171-183
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• 1994

Soil condition, total number of bacteria, soil amylase activity and microbial biomass $(CO_2-C)$ were measured at soil of different forest types. And the difference of the allelopathic effect was determined between fresh leaf extract of Quercus acutissima and Pinus rigida to the bacteria isolated from soil of different forest types. 1. Total number of bacteria in Carpinus laxiflora forest soil was 4~7 times larger than that in pinus desiflora forest soil. 2. Soil amylase activity was positively correlated with total number of soil bacteria and soil organic matter content. The amylase activity at F layer was 4~5 times larger than that at H layer, and that at H layer was 2~4 times larger than that at A layer. 3. Seasonal changes of microbial biomass showed a peak in summer, and vertical distribution of microbial biomass decreased with increasing soil depth. The microbial biomass in Pinus densiflora forest soil was larger than that in Quercus serrata forest soil. 4. Fresh leaf extract of Pinus rigida and Quercus acutissima showed an acceleration or inhibition effect on the growth of soil bacteria, and that of !. acutissima inhibited larger number of soil bacterial strains than that of P. rigida. 4.2% and 25% of soil bacterial strains isolated from soil of P. rigida and Q. acutissima forests were inhibited by fresh leaf extract of P. rigida and Q. acutissima, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.5
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• pp.549-555
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• 2015

Objective of this study was to investigate the effect of carbonized biomass from crop residues on chemical properties of soil and soil carbon pools during soybean cultivation. The carbonized biomass was made by field scale mobile pyrolyzer. A pot experiment with soybean in sandy loam soil was conducted for 133 days in a greenhouse, by a completely randomized design with three replications. The treatments consisted of four levels including the control without input and three levels of carbonized biomass inputs of $9.75Mg\;ha^{-1}$, C-1 ; $19.5Mg\;ha^{-1}$, C-2 ; $39Mg\;ha^{-1}$, C-3. Soil samples were collected and analyzed pH, EC, TC, TN, inorganic-N, available phosphorus and exchangeable cations of the soils. Soil pH, Total-N and available phosphorus contents correspondingly increased with increasing the carbonized material input. The contents of soil carbon pools were $19.04Mg\;C\;ha^{-1}$ for C-1, $26.19Mg\;C\;ha^{-1}$ for C-2, $33.62Mg\;C\;ha^{-1}$ for C-3 and $12.01Mg\;C\;ha^{-1}$ for the control at the end of experiment, respectively. Increased contents of soil carbon pools relative to the control were estimated at $7.03Mg\;C\;ha^{-1}$ for C-1, $14.18Mg\;C\;ha^{-1}$ for C-2 and $21.62Mg\;C\;ha^{-1}$ for C-3 at the end of experiment, respectively, indicating that the soil carbon pools were increased with increasing the input rate of the carbonized biomass. Consequently, it seems that the carbonized biomass derived from the agricultural byproducts such as crop residues could increase the soil carbon pools and that the experimental results will be applied to the future study of soil carbon sequestration.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.5
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• pp.281-286
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• 2005

The effect of oyster shell meal, which is made of a simple crushing and alkaline calcium materials, on soil microbial properties, microbial biomass C, N and P contents, and enzyme activities were evaluated in silt loam soil. The oyster shell meal fertilizer was added at the rates of 0, 4, 8, 12 and $16Mg\;ha^{-1}$. Microbial biomass C, N and P contents were significantly increased with increasing application of oyster shell meal. Soil enzyme activities, such as urease, ${\beta}$-glucosidase and alkaline phosphomonesterase were increased significantly by shell meal application, due to increased soil pH towards neutral range and increased nutrient availability in soil. In particular, the increased microbial biomass P content and phosphomonoesterase activities were strongly correlated with available P content in soil. Conclusively, oyster shell meal fertilizer could be a good supplement to improve soil microbial activities.

• Korean Journal of Environmental Agriculture
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• v.30 no.3
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• pp.234-242
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• 2011

BACKGROUND: Cultivation of winter cover crops is strongly recommended to increase land utilization efficiency, animal feeding material self-production, and to improve soil and environmental quality. METHODS AND RESULTS: Four major winter crops (barley, Chinese milk vetch, hairy vetch, and rye) having different C/N ratio were seeded in silt loam paddy soil in the November 2007 and the aboveground biomass was harvested on the late May 2008 to evaluate its effectiveness as green manure, and root biomass distribution was characterized at the different depth (0-60 cm) to study its effect on physical properties and carbon sequestration in soil. During this experiment, the naturally growing weed in the rice paddy soil in Korea, short awn foxtail (Alopecurus aequalis Sobol), was considered as control treatment. Above-ground biomass of all cover crops selected was significantly higher than that of the control treatment (2.8 Mg/ha). Comparatively higher above-ground biomass productivity of rye and barley (15.8 and 13.5 Mg/ha, respectively) suggested that these cover crops possibly had the highest potential as a green manure and animal feeding material. Root biomass production of different cover crops followed the same trend as that for their above ground biomass. Rye (Secale cereal) might have the highest potential for soil C accumulation (7893 C kg/ha) by root biomass development, and then followed by barley (6985 C kg/ha), hairy vetch (6467 C kg/ha), Chinese milk vetch (6671 C kg/ha), and control (5791 C kg/ha). CONCLUSION(s): Cover crops like rye and barley having high biomass productivity might be the most effective winter cover crops to increase organic carbon distribution in different soil aggregates which might be beneficial to improve soil structure, aeration etc. and C sequestration.